US2513945A - Heater fan combination - Google Patents

Description

July 4, 1950 w. H. KnTo ET AL HEATER FAN COMBINATION 5 Sheets-Sheet l Filed Dec. 14, 1946 July 4, 1950 w. H. Kl'rTo l-:TAL 2,513,945

HEATER FAN COMBINATION Filed Dec. 14, 1946 3 Sheets-Sheet 2 July 4, 1950 w. H. KlTro ETAL.

mm FAN coimNA'rIoN 3 Sheets-Sheet 3 Filed Dec. 14, 1946 Patented July 4, 1950 HEATER FAN COLIBINATION William H. Kitto and Archie J. McMaster, Chicago, Ill., assignors to G-M laboratories, Inc., Chicago, Ill., a corporation of Illinois Application December 14, 1946, Serial No. 716,214

(CL 21B-39) 10 Claims.

Our invention relates to a heater fan combina.- tion.

Broadly, the idea of projecting air through a heating element is old and it has also been suggested to remove or de-energize the heating element so that air at substantially room temperature can be moved by fan blade action. Many such heater fan combinations are of a substantially permanent nature and have been usefully employed for their intended purpose. Attempts to apply the same general idea to portable devices have not been eminently satisfactory for a number ci reasons known to those skilled in the art. In general, portable units have either been unsuccessful as fans or as heaters or as both; or they have been relatively much more expensive than their utility would warrant or they have suffered from other defects 'which have rendered them commercially unacceptable and they have enjoyed only a limited sale.

The principal object of our invention is the provision oi an improved heater fan combination.

Another object is the provision of such a unit which is truly portable and which will perform good service as both a fan and heater.

Another object is to produce a portable heater fan combination which can -be simply and inexpensively manufactured and which can be suitably and easily used ior its intended purpose.

In carrying out our invention, we produce a blower type electric air heater with a removable heater housing having a parting line outside the major diameter of the fan. Electric heater coils are mounted inside the iront shell and connected to the fan motor case with a cord and plug. The air outlet in the front portion of the shell and the air inlet in the rear portion of the cover are such that air flow is restricted to approximately 25% of the volume obtained when the fan is operated as a fan and with the heater shell removed. The fan speed is reduced at least of the order of about 15% when the housing is in position due to the greatly increased horse power required to pass the air through lthe housing, and the speed and load factors fwork out in such a way that substantially the same effect is obtained as if a two speed motor were employed. structurally, the combination of fan, motor housing and fan guard are pivoted to a base, the pivot being between the guard and a pair of upstanding arms supported by the base. The motor housing projects through the rear housing and the housing is mounted outside the fan guard' in such a manner that it also pivots with the remaining portion of the structure when it has been mounted in position. Thus, both the fan and entire heater are adjustable about a horizontal axis so that the air whether heated or not can -be directed to a particular point desired.

Other objects and specific features of the invention will be apparent from a consideration of the following detailed description taken with the accompanying drawings wherein- Fig. 1 is a front elevational view of the heater fan combination of our invention with some of the parts shown in dotted lines to illustrate the position thereof and with the housing carrying the heating elements in position;

Fig. 2 is a rear view thereof;

Fig. 3 is a side elevational view, also with the housing in position;

Fig. 4 is a side elevational view similar to Fig. 3 but with the housing removed;

Fig. 5 is a iront elevational view of the device with the housing removed;

Fig. 6 is an enlarged vertical fragmentary sec tional view showing the housing and the manner of supporting the heating elements therein;

Fig. 7 is a fragmentary, transverse sectional view taken substantially along the line l-'l of Fig. 6;

Fig. 8 is an elevational view of the motor heuslng and contents thereof shown removed from its support;

Fig. 9 is a vertical central sectional view thereof with some of the parts in elevation;

Fig. 10 is a perspective view of a switch ein-l ployed as part of the motor housing assembly;

Fig. 11 is a fragmentary perspective view showing a fastening detail as employed at the top portion of the housing between the two parts thereof;

Fig. 12 is a fragmentary perspective View showing the construction at the side edge of the housing where it engages around the fan;

Fig. 13 is an enlarged sectional view partly in elevation showing a latch arrangement employed at the bottom of the housing; ands Fig. 14 is an exploded perspective View showing the details of the latch construction.

The embodiment of the invention shown in the drawings comprises a base i6 which may be used to support the fan in a generally upright position as indicated in Fig. 4, or which may be provided with a usual type of bayonet slot (note Fig. 2) to support the fan, with or without the heater housing, from a side wall. A yoke Il has associated with it a re-enforcing strip I8, the

yoke and re-enforcing strip being together secured to the base by suitable means, as by screws I8, in the manner particularly indicated in Fig. 1 and Fig. 2. The yoke |1 is shapedto form a pair of upstanding arms to the top of which are pivoted a pivot and mounting bracket 2|. The pivot and mounting bracket 2| comprises simply a :dat transverse metal strip having a pair of right angular end portions 2| (see Fig. 4) through which pivot bolts 22 extend and to which such pivot bolts are preferably substantially permanently secured so that the bracket and pivot lbolts move as a unit. The pvot bolts 22 also extend through the upper ends of the yoke I1 and wing nuts 23 threaded `on the pivot bolts 22 can be tightened to secure the pivot and mounting bracket in substantially movable position with respect to the base.

A cup shaped motor housing 24 has a front closure plate 26 secured thereto by means of a plurality of integral projections 21 whereby to form a firm engagement between the closure plate and the cup shaped housing and the entire motor housing assembly and contents are mounted to the pivot and mounting bracket 2| by securing such member and the closure plate 26 together in any suitable manner as by welding, riveting, or the like. The motor housing carries a motor, as shown generally in Figs. 8 and 9, by means of which a shaft 28 is driven, carrying fan blades 29. The fan blades are protected by a guard 3| of relatively heavy wire, the guard 3| comprisng a number of Wire sections secured together in the manner shown and fastened to the pivot and mounting bracket 2| by welding. To re-eni'orce and strengthen the lower portion of the guard, however, a vertically positioned section 3|' is suitably secured to the closure plate 26 by a screw 32 or other fastening means. The arrangement shown produces a relatively very inexpensive but, in many respects, advantageous assembly of the fan portion of the device only differing from usual fan constructions in that the guard, of which the pivot and mounting bracket 2| comprises an integral part, is pivoted to the base or like support and the motor housing is secured to the fan guard assembly. By contrast, in the usual construction of the prior art, the motor housing is pivoted to a base and the fan guard is secured to the motor housing. The mechanism, as so far described, is very easily assembled for manufacturing purposes as Well as for service purposes. It comprises the motor housing assembly, without the closure plate 26, as one sub-assembly; the guard and parts integral therewith, including the member 2| and closure plate 26, as another sub-assembly; the base, with its yoke |1, as another sub-assembly; and the fan blades as the nal sub-assembly. To assemble, the fan blade assembly is slipped into position within the guard 3|, the housing 24 mounted to the closure plate 26 while at the same time suitably securing the fan blade assembly to the motor shaft and the portion of the assembly already mounted together then secured in pivotal relation to the base` I6. The assembly may be carried out in a different order of steps than described, but it Will be obvious that we have .provided a compact, inexpensively manufactured, but eiiicient, fan device as a part of the combination of our present invention.

The heater shell or housing comprises a front shell 33 and rear cover 34 secured together ina manner to bedescribed along a parting line 36 (see Fig. 3) which is outsidethe major diameter d of the 1an, and, indeed, just outside the major circumference of the guard 3|.

While the front shell portion of the housing may be formed in various ways, we have found a simple inexpensive method to comprise forming a band 31 having a cross section partly shown in Fig. 6 and securing the ends of that band together at asuitable spot in their circumference, preferably coincident with the location of a latch member as will be described. A front portion 38 is suitably formed, as by a drawing operation, and is extended over the front edge,

of the band 31 in the manner particularly shown in Fig. 6 and the parts suitably secured together as by spot welding, low temperature brazing or the like. The front cover 38 has an opening 39 partially closed by a mesh 4|, the mesh being suitably of the expanded metal type to give maximum rigidity coupled with suitable openness as desired in this particular type of installation. A plurality of guards 42 are secured in front of the mesh 4|, preferably in the manner disclosed in the copending application of William H. Kitto, Serial No. 678,794, led June 24, 1946. These guards are preferably shaped in the manner shown in section in Fig. 6 and in plan in Fig. 7, so that their ends engage and are secured to the front portion 38 of the shell at opposite sides of the mesh 4I.

The rear cover 34 generally is shaped like the front portion 38 with, however, a central opening 43 through which the motor housing projects and a plurality of air admitting openings 44 which are also preferably covered with a wire mesh similar to the mesh 4|. The rear cover 34 slips over the edge of the band 31 in the manner particularly indicated in Fig. 6 and is secured thereto in the following manner. The top edge of the band 31 carries an upwardly extending projection on tongue 46 (see Figs. 6 and 11) formed suitably by securing to the underside of the band a small plate 41 which carries the tongue 46, the tongue 46, therefore, projecting upwardly permanently through a slot in the band. The rear cover has a slit 48 through which the tongue 46 projects when the housing is assembled in a manner to be described.

A latch is provided in the bottom portion of the housing constructed in the following manner: A latch bar 49 (note Figs. 13 and 14) is slidable in a channel member 5|, four outwardly extending ears 52 of which lie against the outside bottom surface of the band 31 and are secured together as by welding. The member 5|, therefore, not only functions as a portion of a latch but also to secure the ends of the band 31 together so as to comprise an integral portion of the construction of the housing. A latch spring 53 has one end engaged over a projection 54 on the latch and another end engaging over projection 56 on the channel member 5|. The

spring is tensioned so as to draw the latch 48 in a left hand direction, looking at Fig. 13. A latch projection 51 is adapted to engage a pro- .iection 58 on the rear cover 34, formed thereon by the simple expedient of cutting a slit in the material comprising the rear cover and partially drawing the material at one side of the slit out of the plane of the remaining portion of the cover to leave an outwardly extending projection. The rear cover 34 is secured to the front shell.' therefore, by first engaging the tongue 46 through the slot 48, then bringing the remaining portion of the rear cover into engagement with the front shell and then withdrawing-the latch by engaging the tail piece 59 and drawing the latch member 49 backwardly against the tension 'of the spring 53 to engage the projection 51 over the projection 58. The spring 53 is made strong enough so that the rear cover is rmly held in position in this manner.

To hold the housing in iixed position with respect to the remaining portion of the fan assembly, the cover 34 and shell 31 are provided with edge slots 6| and lil/respectively (see particularly Fig. 12) which surround the pivot bolts 22 when the housing is assembled around the fan guard so that the two portions of the housing, namely, the'band 31 and rear cover 34 are engaged and pinched between the ends 2|' of the pivot and mounting bracket 2| and the inside surfaces of the upwardly extending arms comprising the yoke |1. Since the motor housing projects through the central opening 43 of the rear cover so as to prevent relative tipping movement between the housing and fan assembly, and the relative positions of the two portions of the device are iixed at the two pivot points, the fan and housing will always have the same relation with respect to each other, and the fan and housing can be moved as a unit to direct heated air in any desired direction.

A heating member comprising strands 63 of coiled resistance wire is secured to the heater shell in the path of air projected by the ian through the front opening 39. To support the strands 63 in position, we provide a pair of cross members 84 and 66 of generally channel shaped cross section as shown particularly in Fig. 6 and having end projections 61 (see Fig. 6) shaped to engage the inside surface of the band portion 31 of the heater shell where they are spot welded or otherwise attached to the shell. Thus, the cross members are secured in position in such a manner as to increase the strength and rigidity of the heater shell and at the same time to provide a support for the heater strands 63.

To secure the heating element in position, we provide a plurality of spool shaped resistance and refractory members 68, suitably porcelain, which, by means of screws 69, are attached to the cross members 64 and 66, for instance, in a pattern such as indicated in Fig. l. At opposite ends of the cross member 66,'we provide terminal post assemblies 1|. The strands 63 may, therefore, comprise coil sections of a continuous length of resistance wire, the ends of which are secured to the terminal assemblies lL t will be noted that there are a greater number oi 'turns of resistance wire at the outside portion of the opening 39 than at the center portion thereof. We have, by the means indicated, been able sojto relate the coils of resistance wire to the air passing therethrough, that the air is of substantially uniform temperature as it emerges from the opening 39. The strands 63 are supported closer together at the point of maximum amount of air ow, but the heating surface at a particular point may be controlled in various ways, as, for example, by providing a greater number of coils in the strand and in other ways known to those skilled in the art. We have found a very simple method of producing the coiled strands to be to grasp the central portion oi a wire section with a suitable tool and twist the same while guiding the wire so that the helices are formed with opposite inclinations at the two sides of the point at which the wire is grasped. En this way, it is very simple to coil an intermediate section of a single strand and control the number of turns, thereby in a simple Cai and inexpensive way producing a single strand with intermediate coil strand sections disposed between the fastening loops as clearly shown in Fig. 1.

The heating element is connected into the electrical circuit by means of two properly insulated lead-in wires 12 which are joined to form a single strand double conductor 13 which passes through a grommet 14 in the shell housing and leads to a suitable plug 16 for connection to a source of power in a manner which will be described.

A suitable motor for driving the fan is mounted within the cup shaped housing 24 and comprising a stator consisting of a coil 11 carried on a laminated core 'i8 secured to the cup shaped motor housing by suitable means including mounting screws 19. A suitable rotor, which is not shown in detail in the drawings, carries the shaft 28 journalled in suitable bearings 8| and 82 formed in such a manner as to act as both radial and thrust bearings. These bearings are of such a type as to receive oil from time to time and to deliver oil thereto, we provide a pair of oil tubes 83 suitably formed of plastic and having supporting terminals 84, the Shanks of which extend through holes in the housing, and the flat heads of which are in part engaged by the iiange of a switch 86 to hold the oil tubes in position.v The supporting terminals 84 are in the nature -of hollow rivets which are slightly pinched in at their lower ends as indicated to grasp the plastic tubes and produce substantially a unitary assembly. By delivering oil through the members 84, it passes the tubes 83 and flows to the bearings through apertures therein provided for the purpose. The electric switch 86 is disposed in a rectangular` opening at the top of the motor housing and has spring members 81 at each side thereof so that it can be snapped into position and vwill be held by the springs `81 or can be snapped out of position to dissociate it from the housing. At a. corresponding position, near the bottom of the motor housing, is a combination socket and terminus member 88 held in position by a pair of fastening screws 89 which engage a mounting bracket 9 As noted particularly by reference to Fig. 8, the plug 1E engages in the socket 88 to provide a source of electrical energy to the heating coils. A cord 92 is adapted to be plugged in in a suitable manner to a source of power and is suitably led into the motor nousing 24 where one of its conductors 93 is connected to one side of the switch 8B and another of its conductors 9i! is connected to one terminal of the coil l1. A conductor 9S leads from the opposite switch terminal to the opposite side of the coil l?, and the coil and terminals of sccket or receptacle S8 are suitably connected in parallel so that when the coil 11 is energized the receptacle 38 will also be live. Thus the circuit comprises the switch v3S and coil l1 connected in series and the receptacle .38 connected parallel to the coil so that by operating the switch 36 to On position both the motor and heating element are energized ir" the heating elements are connected into the circuit, or if the heating elements are not connected into the circuit, then the motor will nevertheless be energized and can be operated without the heating coil. The heating element, however, cannot be heated except when the fan is operated.

t the rear of the motor housing, aligned with the coil l1, we provide a, plurality of ioni/ers 9i so that some or the air moved by the fan will pass through the motor housing and be directed against the portion of the motor developing the greatest amount of heat.

4 It will be seen from the above description that the combination device of our present invention can equally well operate as a fan unit or heater unit and in any case is adjustable and simply and easily employed v,'ust as-if it had been designed to perform only a'single function. It will be noted that the top of-the housing is provided with a handle 98 for easy portability when the device is used as a heater, while the guard may act as a handle to carry the fan when the heater housing is not in position. While normally the device is expected to stand on its base, it may be suitably supported, as by means of the bayonet slot 99'indicated in Fig. 2, in which case the base will lie in a verticalV plane and the fan motor and heater housing (if in position) may be rotated a major portion of/ 90 degrees about the pivots to direct air, heated or otherwise, substantially in a horizontal direction.

If the device is to be used only as a fan, it will deliver unheated air if the plug IIB be removed, but preferably the entire housing is removed because there is a substantially greater delivery oi air under such circumstances. To remove the housing, the plug is first removed, the latch at the bottom of the housing disconnected, the wing nuts loosened, and the rear cover 34 removed by first separating it at the bottom and then lifting the slo-t away from the tongue at the top of the housing. The cord is passed through the central opening of the rear cover and it is removed in its entirety. The front housing is then removed by merely separating it from -the'pivots, and the wing nuts are then tightened with the fan in suitable position for operation. The housing may be storedtempoiarily with the rearcover and heater shell latched together in the same manner as when in position around the fan blades. To replace the housing, the reverse' steps are employed. The wing nuts are first loosened, the fan and guard placed in the heater shell, suitably by placing the heater shell on the lap and placing the fan face downwardly in the shell, the cord and motor housing then extended through the central rear opening of the rear cover, and the rear cover then latched to the housing in the intended manner. The band 31 and rear cover 34 will, automatically, be disposed between the pivot and mounting bracket 2l and yoke l1 when assembled in this manner, and when the wing nuts are fastened the assembly will be complete except for insertion of the plug 16 which is required to deliver current to the heating elements.

The combination of our invention may be constructed in various ways and the capacity may be varied. We have obtained good results by providing a construction in which approximately five hundred cubic feet of air per minute are displaced by the ian without the heater housing and approximately one hundred thirty-five cubic feet of air per minute when the heater housing is in position. |The flow of air through the housing should preferably be restricted to somewhere between about 20% and 40% of that of full fan capacity without the housing and suitably about when delivering values of the order described. We have found that by restricting the air intake in the manner described, the fan speed is reduced at least of lthe order of about 15% of full speed without the housing. In some respects this produces the same general effect as obtained by the use of a two speed motor; in other words, permits obtaining the same general advantages without the attendant costs.

There are many details and advantages in the construction of our invention which will be recognized by those skilled in the art but which screws of the switch, and by forming them oiv plastic the possibility of a short circuit or arcing is greatly reduced., The simple manner of securing the metal terminals and holding the tubes in position is also advantageous. It should be noted, also, that the cord 'I3 -is preferably made short enough so that it is impossible to remove tlsie housing without rst disconnecting the plug Some of` the remaining details, particularly as to motor construction and the like may be made the subj ect matter of separate applications. The scope of the invention as directed to the combination fan and heater is defined in the claims.

What we claim as new and desire to protect by Letters Patent of the United States is as follows:

1. In a heater fan combination, a fan structure including a base, motor housing, fan blades and blade guards, operable as a fan, and a plural part heater housing entirely surrounding the fan and guards therefor, the parts being separable at a point outside the major diameter of the ian, the housing having a heating element and means to deliver current thereto, the said housing being apertured to passsubstantially less air than that normally delivered by the fan with the housing removed.

2. A heater fan as defined in claim 1 where- 1 in said heating element is mounted on the inthe heating element, the said receptacle and motor being in parallel series relation with the switch so that both are energized simultaneously.

5. A heater ian as defined in claim 1 wherein said motor housing contains a motor, switch and receptacle for a heater plug, and an oil tube having a top flange engaged by the switch to hold the oil tubes in position to deliver oil to the motor.

6. In a heater fan combination, a fan structure including a base, motor housing, fan blades and blade guards, operable as a fan, and a plural part heater housing releasably secured together about the said guard along a peripheral line outside the major diameter of the fan, the housing having a heating element and means to deliver current thereto, said heating element being nonuniformly distributed in the path of the air, with a greater concentration of heat at places of maximum air iiow, so that the air as discharged is substantially uniformly heated. v 7. In a heater fan, as defined in claim 1, wherein the housing carries a cable and plug for energizing the heating element, said cable being of Vsuch length that it is necessary to remove the plug from its receptacle before the heater housing can be removed from the combination.

8. In a heater fan combination, a fan structure including a base, motor housing, fan blades and blade guards. operable as a Ian, and a plural part heater housing releasably secured together about the said guard along a peripheral line outside the major diameter of the fan, the housing having a heating element and meansto deliver current thereto, the said housing being apertured to pass substantially less air than that normally delivered by the fan with the housing removed, said housing having a cylindrical portion rolled from sheet metal, the ends of which are spaced from each other along a meridian of the cylinder, but secured together by having a latch housing attached thereto, the housing containing a spring and latch functioning to secure separable portions of the housing together.

9. In a heater fan combination. a fan having a support, a motor and motor housing adjustable with respect to the support. and fan blades driven by said motor, all operable asa normal air moving fan. and a housing entirely surrounding said fan blades and separable at its major diameter. said housing being apertured to permit ilow of air therethrough at not more than about seventyve percent capacity of the fan without the housing, and aheatlng element carried by the housing and disposed to heat substantially equally all air passing lthrough the same.

10. A heater-fan combination comprising a base having a pair of upstanding arms, a mounting bracket having :pivot bolts extending into said arms, a motor and housing secured to said mounting bracket, fan blades driven by said motor, a guard surrounding said i'an blades and secured l0 to the mounting bracket, a housing having two principal parts secured together about substantially their major diameter outside the majoi diameter of the fan so as to enclose the fan blades and guard, one such housing part being apertured to permit the motor housing to project therethrough and the other carrying a heating element along the general axis of the fan, the housing being apertured to Dass air equivalent to not more than about seventy-tive percent capacity of the fan, the said housing being disposed between said mounting bracket and upstanding arms when in assembled relation around the fan blades, and nuts threaded on the said pivot bolts to hold the fan and .housing in adjusted rela- I tion, the housing being separable and removable and the said nuts adapted to secure the mounting bracket alone when the tan is employed without the housing.

WILLIAM H. KITIO. ARCHIE J. MCMASTER.

REFERENCES CITED The following references are ci' record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 1,425,546 Russell Aug. 15, 1922 1,633,801 Williams June 28, 1927 1,958,007 MacDougall May 8, 1934 2,149,689 Smith et al. Mar. 7, 1939 2,274,935 Naul Mar. 3, 1942

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